You can pretend that everything is just published on the internet and printing is just something old people do all you like, it is simply not the case yet.
No, I actually stand by my claim.
Only the people at the high end of the print and design industry actually care about things like colour matching and quality.
There are huge swaths of businesses who print stuff who apparently just do not care one bit. Just look around at all the random signage and posters printed for anything that's not a huge advertising campaign and/or by a very large company. The sort of things produced by the large number of smaller regional and local businesses.
The quality is terrible. The typesetting is terrible. The design is terrible.
Just near where I work, there's a barber with a shop sign out the front in the street. It has a picture of a man getting a shave on it. I CAN SEE THE FUCKING PIXELS. I'm not joking, it's eyebleedingly bad. The pixels are huge, the colours are saturated and the kerning on the sign is bad.
Yet the shop seems to do good business.
There are whole bunch of professional people engaged in nothing bud business responsible for comissioning and producing that sign. Given that they didn't care enough to find a picture with adequate pixel density, I think it is fair to claim that they don't care about CMYK.
Almost all stuff is on the low end like that. That's why shops like VistaPrint are popular and very profitable. Most people, even people who need signs and things for professional purposes just do not care.
Yeah, there are some pro photographers and high end design companies, but most of the world is not like that. Most is cheap and cheerful, and most people wouldn't notice pixellation or bad colour matching even if a blue pixellated dog bit them on the leg.
So yeah, most people just don't care and the web has nothing to do with it.